Elevator control system



Dec. 20, 1932. H|GBEE 1,891,710

ELEVATOR CONTROL- SYSTEM Filed March 27, 1928 INVENTOR Ray P. Higbee ATT'oRNEY Patented Dec. 20, 1932 UNITED STATES PATENT OFFICE RAY P. HIGBEE, OF GERMANTOWN, PENNSYLVANIA, 'ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA ELEVATOR CONTROL SYSTEM Application filed March 27, 1928. Serial No. 265,203.

" parting from the usual method'of controlling the elevator by means of an operator carried by the elevator and providing for controlling the elevators by means of suitable control apparatus located at each floor level. In utiliz- 5 ing this method of control, a dispatcher or attendant is stationed at each floor whose duty it is to close the hatchway and car doors and, therefore, set the elevator in operation after it has been automatically landed.

Among the chief advantages to be obtained by utilizing a control system of this type are that all the space inthe elevator car is made available for carrying passengers, the width of the car opening or doorway may be in- A creased and the total moving mass is reduced since the weight of the operator, and control mechanism and an equal amount of counterbalancing is removed.

Another important advantage also is that the proper sequence of car operation may be easily and automatically maintained since the dispatcher at each floor must start each car in turn.

The object of the invention, generally stat ed, is to provide a control system for elevators which shall be simple and (efficient in operation and economically manufactured and installed.

A more specific object of the invention is 40 to provide for controlling the operation of elevators by means of control apparatus located on each floor instead of on the elevator car itself. 7

Another object of the invention is to provide'for the operation of an elevator wherein the elevator is automatically stopped at each floor level when travelling in either the downward or an upward direction, and started each time by an individual operator located at eachfioor level. i

A further object of the invention is to provide a control system for elevators wherein the hatchway doors are automatically opened when the elevator stops in the position opposite the floor landing and closed by an attendant outside the elevator to automatically. start the elevator toward the next floor.

Other objects of the invention will be come evident from the following description taken in conjunction with the drawing, in which, the single figure is a diagrammatic View of an elevator control system embodying my invention.

Referring to the drawing, the control sys tem shown is suitable for operating a single elevator comprising an elevator car C suspended by a cable Ca which passes over a sheavewheel S and a hoisting drum D to a suitable counterweight CW in the usual manner. The hoisting drum D is directly coupled to an elevator motor EM which is illustrated as of the separately excited type.

In this particular embodiment of the invention, the control for the elevator motor EM is of the variable voltage or Ward- Leonard type. However, it is to be understood that any other suitable system might be utilized. The control system, as shown, comprises a motor generator set consisting of a driving motor M of the shunt-wound type having an armature M and shunt field winding MF with its armature M directly coupled to the armature G of the generator G. The generator Gris of the variable voltage compound-wound type having an armature G, a series field winding GSF, shunt field winding GF and a demagnetizing field winding GAF. The armature G of the generator G is connected in loop circuit with thearmature EM of the elevator motor EM.

A suitable source of direct current power, illustrated as line conductors L1 and L2, is provided for supplying power to the system. As shown, the motor-generator set is connected direct to the power conductors L1 and L2, the control apparatus being purposely omitted to simplify the drawing.

. In order to control the operation of the elevator motor EM, the usual up-direction switch 1, clown-direction switch 2 and speed 1 switch 3 are provided. A. pair of direction determining relays and 5 are provided for biasing the elevator system to effect the operation, of the elevator in either an upward or a downward direction thereby rendering only one of the direction switches 1 and 2 responsive to the control of the attendant or dispatcher, as will be hereinafter described in detail.

It is to be understood in connection with the direction determining relays or biasing switches l and 5 that they operate to estab lish control circuits which eliect a reversal of the elevator upon its arrival at a top or bottom terminal point.

In order to control the operation of the b asing switches 4.- and 5 in accordance with the movements of the elevator, a pair of switches, preferably of the limit-switch type, designated as DL, down limit and UL up limit switches, respectively, vhich are mounted in the elevator hatchway and dis posed to engage cam member 6 and carried by the elevator car, as shown.

Suitable hatchway doors, such as are usually provided in elevator control systems, are illustrated and designated by the reference characters D1, D2 and D3, only three of the doors being shown, but it is to be understood that a door is associated with each of the floors past which the elevator travels.

In order to control the movements of the hatchway doors, suitable door operating devices designated as D01, D02 and D03, respectively, are provided. These door operating devices may be of any suitable type whereby the door is given a positive movement to both the open and closed positions. The particular operating devices, as illustrated, comprise an actuating lever 10 pivoted at 7, secured to the door in any suitable manner at 8 and operating about its pivoted point 7, through the agency of either of two solenoid type magnets 9 and 11. The energization of the magnet 11 will cause the door to move in the direction as designated by the arrow X to the open position, while the energization of the solenoid 9 will move the lever 10 to cause the door to be actuated to its closed position as shown in the drawing.

In order to efiect the automatic operation of the door operating devices when the elevator car arrives at the floor landing, a plu rality of cam actuated switches 12, 13 and 14-, respectively, are provided and disposed within the hatchway in such manner as to be actuated in accordance with the movements of the elevator car as will he described in detail hereinafter.

For closing the doors, a plurality ot'pushbutton switches, designated as 15, 16 and 17, are provided at the respective floor levels as shown.

In order that a more comprehensive understanding of the invention may be obtained, a

detailed description of the operation of the system will now be given.

Assuming the elevator car to be at its lowermost terminal point, that is, at the lower floor, the car in this position causes the lower cam member 6 which is carried by the car to engage the down limit switch DL and hold its contact members in the open position. If it be. assumed that the elevator car C has just reached this position after travelling downward from the upper terminal point, it will be understood that the operation of the down limit switch DL operates to deenergize the operating coil of the biasing switch 5 which was determining the operation of the elevator during its downward travel. It will be observed that a circuit extending from the line conductor L2, through the contact members of the down limit switch DL, conductor 19, operating coil of the biasing switch normally closed contact members a of the biasing switch l and conductors 21, 22 and 23, to the line conductor L1, is interrupted and, consequently, the biasing switch 5 will return to its open position.

It will be readily understood that the up limit switch UL is now in the closed position having been held open by the cam member 6 during such time only as the elevator car was at theupper terminal and, therefore, upon the opening of the biasing-switch 5 establishes a circuit extending from the line conductor L2 through the contact members of the switch UL, conductor 25, operating coil of the biasing switch 4, normally closed contact members a of the biasing switch 5 and conductor to the line conductor L1. Upon the establishment of this circuit, the biasing switch 4 is actuated to its closed position thereby biasing the elevator system to I now operate the ole *ator car 0 in the upward directionin response to the control circuits which are established by operating the floor push-buttons 15, 16 and 17 as will hereinafter be described in detail.

Since the elevator car is now in its lowermost position the cam member 24: engages the am switch 12 thereby actuating it to the closed position. The closure of the cam switch 12 establishes a circuit extending from the line conductor L2 through the normally closed contact members 27 of the push-button switch 15, conductor 28, contact members of the cam switch 12, operating coil 29 of the door opening magnet 11, to the line conductor L1 thereby opening the door and maintaining it in the open position.

In order to set the elevator in operation to proceed from the lower terminal, the attendant on the first floor operates the pushbutton switch 15 to bridge its normally open contact members 31 thereby establishing a circuit extending from the line conductor L2 through the contact members 31, operating coil of the door closing magnet 9 and conduc- 'rectionswitch 1 which may be. traced from the line conductor L1, through the door switch 36, conductor 37, door switch 35, con ductor 38, door switch 34, conductor 39, the

normally closed contact members of an inductor type relay 41, conductor 42, the operating coil of the up-direction switch 1, conductor 43, contact member Z) of the biasing switch 4, conductor 25, contact members of the up limit switch UL and conductor 26 to the line conductor L2.

The lip-direction switch 1 is now energized and closes its contact members to establish a circuitfor exciting the generator field winding GF with current in one direction. The field energizing circuitsextend from the line conductor L1, through conductors 44 and 45, contact members a of the Lip-direction switch 1, field winding GF, field resistor 46, conductor 47, contact members I) of the up-direction switch 1, conductors 48 and 49 to the line conductor L2.

It is assumed that according to the usual connection of elevator driving motors, the separately excited field winding EMF of the elevator motor EM is continuously energized from the line conductors L1 and L2 and, therefore, the energization of the generator field winding GF causes the elevator motor EM tostart up and move the elevator car in the upward direction.

In order to control the operation of the speed relay 3, to accelerate the motor EM to full speed, the up-direction switch 1 is provided with contact members cl which are now closed and establish a circuit which extends from a line conductor L1, through conductors 44'and 45, closed contact member (Z, conductor 51, operating coil of the speed switch 3, conductor 52 the series connected and closed contact members of a pair of inductor relays 53 and 54, conductor to the line conductor L2. Upon the closure of the speed relay 3 a circuit is established which short circuits the resistor 46, thus increasing the excitation voltage supplied to the generator field winding GF and consequently causing the elevator motor Elli to accelerate to full speed.

The inductor vrelays such as are illustrated in this system and designated as 41, 53 and 54 are preferably of the type disclosed in the copending application of H. W. WVilliams, Serial No. 190,482, filed May 11, 1927, wherein a switch and a coil are so'mounted upon the elevator car that energization of the coil is ineffective to cause actuation of the switch until the coil and associated iron yoke are brought adjacent a magnetizable iron plate mounted in the hatchway in which theelevator car operates. At such time the energized coil is rendered efiective to operate its associated switch whichmay establish various control circuits.

In this particular embodiment of the invention the inductor relay 41 is associated with the directional switches 1 and 2 and hereinatfterwill be referrel' to as the stop inductor m relay, In accordance with the usual custom, a plurality of inductor plates 56, 57 and 58 are'mounted in the hatchway in inductive relation to the stop inductor relay 41.

Since the inductor relays 53 and 54 are associated with the speed switch 3 which operates to either accelerate or decelerate the ele vator they will be hereinafter referred to as the down-sloW-down inductor and the up slow-down inductor relays respectively. In duct'or plates'designated as 59, 61 and 62 for the up-slow-down inductor 54 and as 63, 64 and 65 for the down-slow-d-own inductor 53 are provided and mounted within the hatchway in such relative position to the floors as to slow down the elevator in order to obtain accurate stopping at the floor levels.

The exact arrangementof the inductor relays 41, 53 and 54 andtheir respective inductor plates is disclosed in acopending application of E. M. Bouton Serial No. 731,921, filed August 14, 1924, systems of control. The copending application shows an arrangement whereby the inductor relays are so mounted upon the car and the inductor plates so mounted in the hatchway that the respective switches will be operated in proper sequence so that the elevator will be decelerated and brought to a stop level with the associated floor. v

When the elevator reaches a position in its upward travel wherethe inductor relay 54 is opposite its inductor plate 59, the relay operates and opens its contact members thereby interrupting the holding circuit previously traced for the speed switch 3 which inserts field resistor '46 in circuit with the generat'or GF and therefore decelerates the elevator motor EM.

, Itwill be readily understood that the elevator now proceeds at alower speed until such a position is reached thatwill bring the inductor relay 41 opposite its inductor plate 57. In this instance, the inductor relay 41 is actuated to its open position thereby interrupting the holding circuit for theup direction switch 1 which is now deenergized and opens its contact members to deenergize the generator GF. I

The energization of the stop inductorrelay is controlled in this instance by a timeios delay relay 66 having contact members 67 and a dash pot element 68 which retards the downward movement of the relay armature or in other words, delays the opening of the contact member 67.

The operating coil of the relay 66 is connected across the armature EM of the elevator motor EM and is responsive to a predetermined voltage being applied thereto. The contact members 67 are shown connected in circuit with, the up coil of the stop conductor relay 41. Therefore, it will be readily understood that the elevator motor EM operates for a predetermined time interval before the inductor relay 47 is energized. Thus, while the circuit for the coil of inductor relay 4:1 is again closed at the up-direction switch 1, the circuit is not completed until the car has moved relay 11 away from plate 56.

When the elevator motor EM is decelerated and stopped to position the elevator at a floor level, it is desirable to maintain the stop inductor relay in its inoperative or open position until either of the door switches 34, 35 and 36 are opened and this result is accomplished by the operation of the dash pot 68 to delay the opening of the relay 66.

Simultaneously with the stopping of the car level with the second floor due to the operation of the inductor relay 11, the hatchway door D2 is automatically actuated to its open position. This operation is effected by the closure of the cam switch 13 by the cam member 21 which establishes an energizing circuit for the operating coil 71 of the door opening device D02 which extends from the line conductor L2 to the normally closed contact members of the push-button switch 16, contact members of the cam switch 13, coil 71 to the line conductor L1.

In order to provide for controlling the operation of the inductor relays 53 and 54 in their proper sequence, the biasing switches 4 and 5 are each provided with contact members designated as c which are, as shown, connected in series with the operating coils of the inductor relays the contact members a of the biasing switch 4 being disposed to control the operation of the up-slow-down inductor relay 54 and the contact members 0 of the biasing switch 5 being disposed to control the operation of the down-slow-down inductor relay 53. Therefore, it will be understood that since the biasing switch 4 is now in the closed position the coil for inductor relay 5st only is energized and consequently the operation of this system is not affected when the inductor relay 53 passes its inductor plates on its upward travel.

The operation of the elevator may be continued towards the upward terminal point by the actuation of the push button switch 16 by the attendant on the second fioor which, as described hereinbefore, actuates the hatch way door D2 to its closed position thereby establishing an operating circuit for the u direction switch 1. The elevator will then stopped at each floor as described for the second floor stop.

It will be readily understood that when the elevator reaches its upper terminal point, in this case the upper. floor, that the cam member 6 engages the up limit switch UL simultanenously with the engagement with the switch 14 by the cam member 24 therefore interrupting the holding circuit for the biasing switch 4. Since the cam member 6 engages the' down limit switch DL onl while the elevator is in its lowermost position this switch is closed which establishes an operating circuit for the down biasing switch 5 upon the operating of the up biasing switch 4 to the open position. This circuit may be traced from line conductor L2, through down limit switch DL, conductor 19, operating coil of the down biasing switch 5, normally closed contact member a of the up biasing switch 4, conductors 21, 22 and to the hue conductor L1.

It will be readily understood that the operation of the system with the elevator car traveling in the downward direction is the same as that described hereinbefore for the upward travel and, therefore, it is not deemed necessary to describe this operation in detail.

It may be stated in conclusion that, while the illustrated example constitutes a practical embodiment of my invention, I do not wish to limit myself strictly to the exact details herein illustrated since modifications of the same way be made without departing from the spirit of theinvention as defined in the appended claims.

I claim as my invention:

1. In an elevator control system, in combination, an elevator operable in a hatchway past a plurality of floors, a door for said hatchway at each floor, motive means for the elevator, means for controlling the movements of said elevator, said control means comprising means for automatically stopping the elevator at each floor, means for automatically opening the hatchway door upon the arrival of said elevator opposite a floor landing, means mounted remotely from said elevator for simultaneously closing the hatchway door and starting the elevator, and means for biasing said elevator to provide movement thereof in a predetermined direction until all of said floors have been passed in either direction of travel.

2. In an elevator control system in combination, an elevator operable past a plurality of floors, a door at each floor, means for controlling the operation of said doors in accordance with the movement of the elevator, said means comprising means for automatically opening said doors when the elevator reaches the floor level, means mounted remotely from said elevator for closing said doors, and means responsive to the closing of said door for starting the elevator in operation toward the next floor.

3. In a control system for an elevator car arranged to stop regularly at each floorof a predetermined group of floors, means for stoppingsaid car at each of said floors, and switch means individual to each of said floors operable to dispatch said car from the associated floor to the next of said floors.

at. In a control system for an elevator car arranged to stop regularly at each floor of a )redetermined 'rou of floors means for stopping said car at each of said floors, a door at each of said floors and closing mechamsm therefor, switch means for actuating said closing mechanisms, and means responsive v to the closed condition of all of said doors for starting said car.

5. In a control system for an elevator car operable past a pluralityoi floors, means for stopping said car at each of said floors, a door at each of said floors and closing mechanism therefor, switch means individual to each of said floors operable to actuate the closing mechanism for the door at the associated floor and dispatch said car from the associated floor to the next of said floors.

6. In a control system for an elevator car operable past a plurality of floors, means for stopping said car at each of said floors, a door at each of said floors and closing mechanism therefor, switch means individual to each of;

said floors operable to actuate the closing mechanism for the door at the associated floor, and means responsive to the closing of that door for dispatching said car from the associated floor to the next of said floors.

7. In a control system for an elevator arranged to stop regularly at each floor of a- ,predetermmed group of floors including two terminal floors, means for stopping said car i at each of said floors, a manually operable switch for each of said floors operable to dispatch sa-id car from the associated floor to the next of said floors, and means adapted to prevent reversal of said car except at said terminal floors.

8; In a control system for an elevator car arranged to stop regularly at each floor of a predetermined group of ,floors, means for stopping said car at each of said floors, a manually operable switch for each of said floors, up controlling means and down controlling means adapted to respond to said switches for dispatching said car from the floor associated with an operated switch to the next of said floors, and directional switching meansfor determining which of said controlling means will respond to operation of said switches.

9. In a control system for an elevator car arranged to stop regularly at each floor of a predetermined group of floors, means for stoppingsaid car at each of said floors, a manually operable switch at each of said floors operable to dispatch said car from the associated floor to the next of said floors in either direction, and directional mechanism for determining what direction said car will move in response to operation of said switches.

10. In a control system for an elevator arranged to stop regularly at each floor of a predetermined group of' floors, means for stopping said car at each of said floors, a door at each of said floors and closing mechanism therefor, switch means for actuating said mechanisms, means responsive to the closed condition of all of said doors for starting said 0 r, and directional mechanism for determining what direction said car will move in re sponse tothe closed condition of said doors.

11. In a control system for an elevator car arranged to stop regularly at each floor of a predetermined group of floors, means for stopping said car at each of said floors, a door at each of said floors and operating mechanism therefor, switch means individual to each of said floors and operable to actuate said operating mechanism to close the door at the RAY P. HIGBEE. 

